L compound for PAH biodegradation research (Seo et al. 2009; Roy et al. 2012). 3 bacteria strains had been 1st isolated and reported in 1928 for their degradation of phenanthrene (Evans et al. 1965), which initiated research of bacterial degradation of PAHs. Evans et al. (1965) proposed metabolic pathways of phenanthrene by pseudomonas aeruginosa through 3,4-dioxygenation to form 1,2-dihydroxynaphthalene which then enters in to the naphthalene pathway. Since then, a wide range of bacteria have been reported for their biodegradation functions. For instance, the gram-negative bacteria include Alcaligenes sp. (Deveryshetty and Phale 2010; John et al. 2012), Anthrobacter sp. (Kallimanis et al. 2007; Kallimanis et al. 2009), Burkholderia sp. (Dandie et al 2004; Search engine marketing et al. 2007b), Martelella sp. (Feng et al. 2012), Micrococcus sp. (John 2012), Ochrobacterum sp. (Ghosal et al. 2010), Pseudomonas sp. (Rodrigues et al. 2005; Zhao et al. 2009), Sphingomonas sp. (Pinyakong et al. 2000; Roy et al.2012), Staphylococcus sp. (Mallick et al. 2007) and Stenotrophomonas sp. (Juhasz et al. 2000). The gram-positive bacteria incorporate Brevibacterium sp. (Samanta et al. 1999 ), Mycobacterium sp. (Moody 2001; Hennessee et al. 2009), and Rhodococcus sp. (Song et al. 2011). Metabolic pathways of phenanthrene and other PAHs by different bacterial species have been documented (Meckenstock 2004; Search engine optimisation et al. 2009). The initial dioxygenation frequently takes spot at 1,2-, 3,4- and 9,10-carbon positions of phenanthrene. Subsequent meta-cleavage in the resultant diols from 1,2- and 3,4dioxygenations led to the formation of 2-hydroxy-1-naphthoic acid and 1-hydroxy-2naphthoic acid, respectively (Search engine marketing et al. 2009).NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptStenotrophomonas maltophilia (formally known as pseudomonas maltophilia) can degrade PAHs.91511-38-5 In stock S.DBCO-PEG4-NHS ester manufacturer maltophilia strain VUN ten,003 is extremely capable of degrading not just low molecular weight PAHs (i.PMID:33730323 e., 2? rings), but also high molecular weight PAHs ( 4 rings) including benzo[a]pyrene, dibenz[a,h]anthracene, and coronene (Juhasz et al. 1996, 2000, 2002). Some other species in the genus of Stenotrophomonas also can degrade acenaphthylene, phenanthrene, chloroanilines and chlorocatechol (Andreoni et al. 2004; Radianingtyas et al. 2003; Nayak et al. 2009). To our information, bacterial degradation of 6?7 rings PAHs was reported only with S. maltophilia (Juhasz et al. 2000). Stenotrophomonas sp. can degrade acenaphthylene via 1,2-dihydroxy-naphthalene, salicylate and catechol (Nayak et al. 2009). Recent studies suggested that S. maltophila could have at least two unique dioxygenases (NCBI access number : AY588578.1, and AY588576.1), that are highly homologous with naphthalene dioxygenases from other gram-negative bacteria. Having said that, detailed metabolism of phenanthrene is still uncertain in Stenotrophomonas spp.Our prior preliminary study with S. maltophilia C6 indicated that this strain could make use of phenanthrene (Search engine optimization et al. 2007a). In the present study, we have focused the isolation and identification of metabolites of phenanthrene and described a detailed metabolic map. Along with the previously reported pathways, strain C6 can metabolize phenanthrene through numerous pathways. To our knowledge, this can be the initial study of detailed metabolic pathway of phenanthrene by S. maltophilia. Understanding of metabolic pathways may well cause improvement of improved bioremediation technologies for cleaning up PAH contami.